The present invention relates generally to laser aiming devices for weapons such as compound bows, crossbows, handguns, rifles, shotguns, or muzzle-loaders. More specifically, the present invention relates to a quick-mounting, modular laser aiming system for firearms capable of precision windage and elevation adjustments for accurate shooting.
Optical sights such as telescopic rifle scopes have long been in use by hunters for improved sighting. Optical sights involve the development of unique visual skills by the hunter. Typical scopes comprise an optical sighting tube mounted above and parallel to the rifle barrel. A sighting grid is defined within the tube by crosshairs or similar markings. The scope is positioned above and parallel to the gun barrel, so that the scope line of sight extends generally parallel to the line of fire extending from the gun barrel. When a scope is mounted, it must be "sighted-in" before use.
Ideally it is desired to mechanically position the scope cross hairs so that they cross exactly in the middle of the field of view. After course mounting adjustments are made, "fine tuning" of the cross-hair mechanisms will follow. The scope must be adjusted for "elevation" so that the telescopic line of sight converges with the line of fire (i.e. the bullet's impact point) at the target area a predetermined distance from the gun. Elevation adjustments are commonly made, for example, to adjust for varying target ranges. Elevation adjustments are needed when the rifleman switches between different cartridges, which may vary in bullet weight and powder characteristics. Typical scopes also readily facilitate "windage" adjustments to compensate for crosswinds which result in lateral displacement of the fired bullet. Thus, a target shooter employing optical sights of this kind may estimate the firing distance to the target, adjust the scope elevation for the proper distance, and then make appropriate windage adjustments to compensate for cross winds.
The scope is particularly useful under open range conditions or when visibility is particularly good. There the hunter may be afforded the opportunity to carefully scope and visually track his prey until exact targeting is achieved.
However, such scopes are too cumbersome and impractical for use by hunters and others such as law enforcement officers operating in close-range firing situations, where quick and accurate aim is critical. Where visibility is limited by weather or by dense brush such as that typically encountered in the Southern United States, for example, the hunter will not have the opportunity to carefully visually track his target for any extended period. Typically, a deer or other prey will suddenly appear out of the brush, and the hunter will have one opportunity to aim and fire as quickly as possible before the prey disappears again into the dense bushes. The first shot must therefore strike directly on target and produce a kill, so that the deer will not escape injured to die a slow and painful death in the brush. Hence, under such circumstances, quick, unencumbered, and accurate aim is extremely important.
Close-range, quick-fire accuracy is also very important to the law officer engaged in handgun combat. The law enforcement officer may have only a brief view of his assailant. The officer will rarely have time or opportunity to carefully contemplate his aim before firing. The failure to quickly aim and fire at short range could result in the escape of the assailant or the death of the officer. Hence, it can be extremely important that the officer's weapon be equipped with a highly accurate and extremely reliable quick-sighting devices.
Laser aiming devices have been employed in recent years to improve firing speed and accuracy. However, it has proven difficult to adapt laser aiming devices to use with conventional weapons. Laser beam emitter tubes are delicate and highly sensitive instruments. They may be easily damaged by careless handling and exposure to the elements. Additionally, the extreme recoil shock produced by conventional hunting weapons and handguns may severely affect fine laser aiming adjustments and may completely disable the aiming device. Finally, as with the introduction of any new technology, the introduction of laser aiming devices for use with hunting weapons required hunters to learn new sighting methods. To achieve best results in all conditions, a hunter must develop competence in the alternate use of both optical sighting and laser aiming techniques.
Laser aiming devices are typically mounted parallel to the barrel of a weapon such as a rifle or handgun. Conventional gas lasers typically comprise an elongated laser tube containing a helium-neon or other gaseous medium. The gas imparts optical regenerative gain (or "light amplification") to light traveling along the laser tube. Pairs of lenses or mirrors mounted at either end of the gas tube reflect the light back and forth in the tube until it becomes a high-energy coherent beam. The beam illuminates a reference spot or point on the target surface. These non-refractive laser beams are capable of returning a red signal from long distances, typically between five and eight hundred feet.
When the laser aiming unit has been properly pre-adjusted for a predetermined range, the light beam converges with the line of fire and the hunter's line of vision at the target point, so that the hunter may merely "spot" the target by aiming the red beam on the desired strike point before firing. Thus, the hunter is free to brace the weapon with his hand, shoulder, hip, or in any other convenient position while visually sighting his close-range target without a scope or other intermediate optical sighting device associated with the weapon. This freedom is particularly important for close-range, quick-strike firing such as is practiced in dense brush hunting or in hand combat.
Numerous laser aiming devices have been proposed in the prior art for use with hand-held weapons of various types. The development of the laser art is outlined in detail by Matthews in the prior art disclosure of his U.S. Pat. No. 4,313,272, issued Feb. 2, 1982. For purposes of this discussion, the Matthews '272 disclosure is incorporated by reference herein. As indicated therein, much of the early art was directed to providing adequate recoil shock resistance for the laser emitter. For example, various shock-resistant mountings are proposed by Snyder, in U.S. Pat. No. 4,026,054, issued May 31, 1977; U.S. Pat. No. 4,079,534, issued Mar. 21, 1978; U.S. Pat. No. 4,161,076, issued July 17, 1979; and U.S. Pat. No. 4,295,289, issued Oct. 20, 1981.
Each of the above referenced patents relates to laser aiming devices for conventional weapons which incorporate mechanically yieldable shock-absorbing mechanisms to prevent damage from recoil shock. Snyder also proposes quick-change mounting means for mounting interchangeable laser units onto different types of weapons. Very modern laser devices employ solid-state laser emitters, so that such shock-absorption devices are less critical.
Another line of related prior art patents is directed more specifically to the development of laser mounts which provide accurate elevation and windage adjustments Earlier systems applied technology developed for optical scope mounts such as those disclosed by Heinze in U.S. Pat. No. 3,040,433 issued June 26, 1962 and Ivy in U.S. Pat. No. 2,645,855 issued July 21, 1953. Typical scope mounts employ a plurality of cooperating screws which contact the outer periphery of the front and rear ends of the scope. By tightening or loosening various screws, the scope may be realigned for elevation and windage adjustments.
However, because the laser emitter tube is such a delicate instrument and because close-range accuracy from any number of firing positions is important, these prior art scope mounting systems have proved inadequate. A patent more specifically applicable to laser adjustment systems is Matthews U.S. Pat. No. 4,313,272, issued Feb. 2, 1982. The delicate laser emitter tube is securely housed within a rigid casing associated with the gun barrel. Within the casing, the laser tube is captured between cushioned block members which may be mechanically raised or lowered for elevation adjustments. Matthews also proposes alternatively the use of optical beam deflecting prisms for fine elevation and/or windage adjustments. In the latter-referenced system, a pair of wedge-shaped prisms are mechanically rotated to redirect the exiting laser beam. The last-referenced system, however, is very sensitive and expensive, and thus impractical for hunter's purposes.
Kaelin U.S. Pat. No. 4,244,131 issued Jan. 13, 1981, discloses a laser mounting system in which vertical and horizontal adjustments are facilitated by manipulation of the entire laser housing relative to the gun barrel rather than movement of the laser emitter tube within the housing. The Kaelin '131 laser housing also encloses the battery power system. While the system is rugged and readily adapted for use with heavier weapons such as submachine guns, it is too large and cumbersome for use with smaller weapons such as handguns, compound bows, and hunting rifles. Finally, Kaelin's system is incapable of the extremely fine elevation and windage adjustments required for close-range hunting.
U.S. Pat. No. 4,571,870, issued to Heidemann on Feb. 25, 1986, describes a quick-release laser aiming mount for use with a rifle. The mount comprises front and rear rings which axially engage the rifle barrel and are mechanically linked to a tubular bracket which supports the laser unit below the rifle barrel. A calibrated thumbscrew associated with the front ring provides elevational adjustment. A spring-biased thumb wheel associated with the rear of the mount facilitates windage adjustments. The device is not readily adaptable for use with different types of hunting weapons. The main disadvantage associated with the '870 system, however, is that the screw-controlled adjustment system is incapable of providing extremely fine adjustments as are needed in close-range situations.
It will be appreciated that the precision of aiming adjustment achieved in such mounting systems is directly related to the size and spacing of the set screw threads. Some laser systems known to us are equipped with very fine adjustment screws having eighty threads per inch. However, based on our experience, an 80-thread screw turned 1/24th of a turn may move the line of aim one half to one inch at one hundred yards. This produces a substantial aim error which could result in loss of the prey in close, quick-fire situations.
Finer thread screws having eighty-four threads per inch have been used in some laser aiming devices. However, it is our experience that these very fine threads are so delicate that they are incapable of maintaining proper position when exposed to shock from recoil or rough handling of the weapon. Screw threads have been machined as far as possible by present experience and understanding of the art. Hence, it is desired to produce a more reliable, precision adjustment system for laser aiming devices which can achieve very precise adjustments for close-range firing, and which remain true despite shock experienced from rough handling, recoil shock, and unfavorable environmental conditions.
None of the prior art laser aiming systems known to us permit the alternative use of the laser aiming system with an optical sighting system such as a scope. Because scopes are equipped with outwardly protruding windage and elevation adjustment knobs, a laser scope could not be mounted directly upon or around a rifle scope without interfering with the use of the scope. Moreover, no prior art laser aiming device is adapted to be used on various different types of weapons such as rifles, shotguns, and hunting bows.
Hence it is desired to provide a laser aiming system which is durable and readily adapted for use with different types of hunting weapons used in close-range, quick-fire situations. It is required that such a system be capable of precision adjustments in laser sight aiming. Further, such a system should be capable of use with telescopic sights of varying types and diameters.